Crankcase ventilating system



Jan. 7, 1964 H. H. DIETRICH CRANKCASE VENTILATING SYSTEM Filed Feb. 4,1963 A T TORNEV United States Patent O Motors Corporation, Detroit,Mich., a corporation of Delaware Filed Feb. 4, 1963, Ser. No. 255,884 7Claims. (Cl. 12S-119) This invention relates to crankcase Ventilatingsystems for internal combustion engines, and more particularly to acrankcase ventilation valve assembly which may be secured to or form aportion of the usual engine carburetor to receive and disperse crankcasefumes and blow-by gases.

In the design and operation of internal combustion engines, andparticularly engines for motor vehicles, the elimination or dispersionof crankcase fumes and blow-by gases is becoming more and moreimportant. It has been thought that the crankcase fumes and blow-bygases from the engine are a contributing factor to smog problems inVarious regions of the country. It is thus desirable to provide somemeans for consuming or otherwise eliminating the obnoxious gases duringthe operation of the engine for the Vehicle.

There are many available crankcase Ventilating systems and crankcaseVentilating Valves. These are generally attached to some portion of theinduction system of the engine to convey the crankcase gases to theintake manifold, and thus eliminate the gases by the combustion processin the engine cylinders. Most of these systems and Valves areexceedingly complicated and cumbersome and do not provide complete rangecontrol of the crankcase fumes and blow-by gases. For example, many ofthese devices provide positive crankcase ventilation only during certainconditions of operation of the engine, as under high speed conditions.Others provide positive crankcase ventilation only for low speedoperation. A further problem in the generally available crankcaseVentilating valves is in the clogging of the various passages andorifices through which the crankcase fumes and blow-by gases must pass.These orifices are generally of critical size and must be kept clean.They tend to clog with sludge, Varnish formation and other impuritieswhich are carried by the crankcase fumes and are deposited in the smallsized metering orifices.

The device in which this invention is embodied comprises, generally, acrankcase Ventilating valve assembly which is operable under allconditions of operation of the internal combustion engine so thatcrankcase fumes and blow-by gases may be conveyed to the intake manifoldat all times. The valve is also provided with a means for maintainingthe critical metering orifice in an unclogged condition by means of apin which is reciprocated into and out of the orifice in accordance withintake manifold vacuum.

With a device of this nature the majority of crankcase fumes and blow-bygases will be consumed and dispersed regardless of engine load oroperating conditions, providing more efficient crankcase ventilation forthe engine. The metering orifice clean-out means contributeslto thisfunction in assuring proper gas and fume passage through the valveassembly without added restriction.

These and other advantages will become more apparent from the followingdescription and drawing, in which:

FIGURE 1 is an elevational View of a portion of an internal combustionengine, illustrating the various parts thereof;

FIGURE 2 is a cross-sectional View of the crankcase Ventilating Valveassembly embodying this invention and a portion of the carburetor forthe engine illustrated in FIGURE 1; and

FIGURE 3 is an isometric View of the metering oriiice lCe clean-out pinwhich is a part of the Ventilating valve assembly illustrated in FIGURE2.

Referring more particularly to the drawing, FIGURE l best illustrates atypical internal combustion engine with which the invention may be used.The engine, illustrated generally by the numeral 10, includes the usualengine block 12, having formed therein the conventional engine cylindersand reciprocating pistons which are not shown. Secured to the engineblock 12 is a rocker arm cover 14 which is generally a sheet metalmember covering the valve operating mechanism for the engine. Securedbelow the engine block 12 is the usual crankcase 16 in which is locatedthe engine crankshaft and which also serves as a reservoir for theengine oil. Mounted on the side of the engine block 12 is an intakemanifold 18 having ram tubes or pipes 20 which communicate with theengine cylinders through the intake valves in the normal fashion.Adjacent intake manifold 18 is an exhaust manifold 22 to which issecured an exhaust pipe 24 for conveying exhaust gases from the cylinderto the usual mufiier and tailpipe assembly.

Mounted above the intake manifold 18 is a carburetor, illustratedgenerally by the numeral 26, which provides for the proper air and fuelmixture conveyed to the engine cylinders through the intake manifold 18.Mounted above carburetor 26 is an air cleaner-silencer assembly 28 toreceive and filter the incoming air for passage to the engine.

Disposed adjacent to the carburetor 26, or forming a part thereof, isthe crankcase Ventilating Valve assembly, illustrated generally by thenumeral 36. A tube or conduit 32 communicates between the enginecrankcase 16 and the valve assembly 3b. It is to be understood that thetube 32 need not be secured directly in the crankcase but could just aswell be secured in any other part of the engine where crankcase fumesand blow-by gases circulate. For example, tube 32 could alternatively besecured in the rocker arm cover 14.

Referring now to FIGURE 2, the crankcase Ventilating Valve 3) and itsVarious parts are best illustrated. The carburetor 26 includes athrottle Valve 34 mounted on a pivot pin 35 which is suitably secured inthe carburetor throat 38. The carburetor is shown to be mounted on theintake manifold 13 by bolts 4i) although any suitable mounting may beprovided.

Located adjacent carburetor throat 38 is a housing 42 containing anaccumulator chamber 44. Housing 42 may be an integral portion of thecarburetor 26, as illustrated in FIGURE 2, or may be a separate housingsecured to the carburetor 26 in any suitable fashion. The housing 42 isclosed by a second housing member 46 secured thereto in any suitablefashion and which receives an inlet tube 43. Inlet tube 4S is suitablysecured to the crankcase tube 32 and serves as an inlet to theVentilating valve assembly 30. Tube 48 is provided with an inclined end50 for purposes to be later described. A transverse outlet aperture 52is provided in the tube 48 adjacent and spaced from the inner end 50.

Housing 46 also has a passage S4 formed therein which is in registrywith the aperture 52 formed in the inlet tube 48. The passage 54communicates with another passage 56 formed through the wall of thecarburetor 26, the passages S4 and 56 being separated by a meteringorifice 58.

Also formed in housing portion 46 and with a cover member 6) is a hollowchamber 62 located adjacent the metering orifice 58. Chamber 62 isdivided into two portions by a movable partition 64 which may take anyconvenient form, such as a disk spring or a movable diaphragm. Oneportion of the chamber 62 communicates with the atmosphere throughpassage 66 and the other portion of chamber 62 communicates with thepassage 56 through a suitable passageway 68 formed in the housing 42,housing member 46 and the cover means 60. It is thus seen that theright-hand portion of the chamber 62 will be maintained at the samepressure as that of passage 56 and the intake manifold.

Secured to the movable partition 64 is the metering orifice clean-outpin, indicated generally by the numeral 70. This pin is best illustratedin FIGURE 3 and is shown to include a shank portion 72 extending from anenlarged head 74 and terminating in an annular edge 76. Adjacent edge 76is a portion 77 of reduced diameter to permit flow around the pin. Pin70 is secured in any suitable manner to the movable partition 64 and isshown in FIGURE 2 to extend into the metering orifice 58. It may be seenthat as the partition 64 moves from left to right, as Viewed in FIGURE2, in response to intake manifold vacuum and further by the biasing ofspring 73, the `cutting edge 76 of the pin 70 will be withdrawn from themetering orifice 58, and upon movement of the partition in the oppositedirection the cutting edge 76 of the pin 70 will again enter and reamthe metering orifice 58.

Mounted in the chamber 44 of housing portion 42 is a check Valve,illustrated generally by the numeral 80. Valve 8f) is of suflicient sizeto cover the end 50 of the inlet tube 48 and is pivotally secured in thechamber 44 by means of pivot pin 82. Pivot pin 82 is received in abifurcated block 84 secured to the housing member 46 and in the chamber44 by means of suitable bolts or screws 86.

Extending from the chamber 44 through the wall of the carburetor 26 andinto the induction passage 38 is an ejector tube 88, the purpose forwhich will be later described.

T he operation of the crankcase Ventilating valve assembly will bedescribed as follows. Considering first the condition wherein the engineis operating at high load, for example, with the throttle valve 34one-half open or more, as in the position shown in dashed and dottedlines in FIGURE 2, the intake manifold depression will be relatively lowand blow-by in the engine cylinders will be relatively high. Assume forpurposes of discussion that the pressure is inches of mercury or belowin the intake manifold 18 under this condition of operation. With suchvacuum pressure in the intake manifold, which Vacuum will be conveyed tothe inlet tube 48 through the passages S6 and 54, the check valve 80will be in an open position, that is, as illustrated in dashed anddotted lines in FIGURE 2. Crankcase fumes and blow-by gases will thus bedrawn through the tube or pipe 32, the inlet tube 48 and'past the checkvalve 80 to the accumulator chamber 44. Air flowing past the injectortube 88 will create an additional ejector effect to draw the crankcasefumes and blow-by gases from the accumulator to the carburetor inductionpassage 38 and into the intake manifold.

Assuming now the engine is operating at light engine load, that is,where the throttle valve 34 may be one-half open or less, the intakemanifold depression will be relatively high, for example, at 15 to 18inches of mercury. This suction or Vacuum pressure conveyed throughpassages 56 and 54 is sufficient to close or partially close check valve80 and thus close the end of the intake tube 48 requiring the crankcasefumes and blow-by gases to be conveyed through the passages 54 and 56,through the metering orifice 58 and into the induction passage 38 of thecarburetor 26 below the throttle valve 34. Thus, at light and idle loadthe crankcase fumes and blow-by gases are ejected into the intakemanifold without adversely affecting the carburetion characteristics ofthe engine.

Considering now the effect of engine operation on the metering orificeclean-out means, the movable partition 64 is shown in full lines in theposition it would assume under high engine load, that is, 15 inches ofmercury and below in the intake manifold. Under these conditions thecrankcase fumes and blow-by gases are conveyed past the check valve 80and into the induction passage 38 above the throttle valve 34. However,upon decreasing the engine load or closing the throttle 34 the intakemanifold depression builds to cause the movable partition 64 to be drawnto the right as Viewed in FIGURE 2, withdrawing the pin 70 from themetering orifice 58. The partition 64 and pin 70 are held in thisposition until the engine load changes, at which time manifolddepression `decreases and the flow is again through the accumulatorchamber 54. The movable partition 64 will again move to the left asViewed in FIGURE 2, and the cutting edge 76 of the clean-out pin 70 willream metering orifice 58 thus keeping it free of :sludge and Varnishdeposits. This operation is automatic, being dependent upon the amountof Vacuum in the inlet manifold 18 during various conditions ofoperation of the engine.

`Contributing greatly to the efficiency and operation of the Ventilatingvalve assembly 30 is the position of the check valve Si), that is, thepivot pin 82 must be properly positioned bot-h vertically andhorizontally within the accumulator chamber 44. Furthermore, the angleof the end 5t) of the inlet tube 48 s important. The proper combinationof pivot pin location and tube end angle provides a linear flow through`the metering orifice 58 when the check valve 80 is open, that is,linear with respect to manifold depression because of the modulatedposition of the check valve 8f). This is extremely desirable forefficient operation of the Ventilating valve assembly.

Thus, a crankcase Ventilating system is provided which is `operableunder all conditions of engine operation for better dispersal andelimination of obnoxious fumes from the engine. The Ventilating Valveassembly is operable under both high and low engine load conditions,being dependent upon manifold depression for its actuation. Propercarburetion characteristics are retained through the use of a meteringorifice which will not become clogged or fouled `due to the passage offumes and blowby gases therethrough.

What is 4claimed is:

l. `Crankcase Ventilating means for an internal combustion engine havinga carburetor including a throttle valve and an inlet manifold andcomprising:

a valve body connected to said carburetor and having first and secondoutlet means, said first outlet means communicating with said carburetorupstream of said throttle valve, said second outlet means communicatingwith said carburetor downstream of said throttle valve and including ametering orifice;

conduit means communicating between said crankcase and said valve bodyand communicating with said first and second outlet means;

a check Valve in said first outlet means and operable in accordance withthe amount of suction in said inlet manifold to direct crankcase gasesthrough either said first outlet means or said second outlet means;

and vacuum operated means for cleaning said metering orifice, said meansbeing operable in accordance with the amount of suction in said inletmanifold.

2. A crankcase Ventilating device for an internal combustion enginehaving an inlet manifold and a carburetor including a throttle valve andcomprising:

a valve body adapted to be secured to said carburetor, said valve bodyhaving an inlet land first and second outlets, said first outletcommunicating with said carburetor upstream of said throttle valve andsaid second outlet communicating with said carburetor downstream of saidthrottle Valve land having a metering orifice therein;

a check Valve mounted in said valve body and in said first outlet, saidcheck valve being operable in accordance with the vacuum pressure insaid inlet manifold to direct incoming gases through either said firstor second outlet depending on said vacuum pressure;

conduit means communicating between said engine crankcase and said inletin said Valve body;

and vacuum responsive means for cleaning said metering orifice in saidsecond outlet, said means including a chamber formed in said valve bodyand a pin extending from said chamber and into said metering orifice andspring means in said chamber and secured to said pin and movable inresponse to manifold vacuum to move said pin into and out of saidmetering orifice.

3. In a crankcase Ventilating valve for an internal combustion engineyand having a metering orifice in an outlet therefrom, means forcleaning said metering orifice comprising:

a housing having a chamber formed therein;

a pin member having an enlarged head disposed in said chamber landextending from said chamber and into said metering orifice;

a disk spring in said chamber secured at the center thereof to saidenlarged head and secured at the edges thereof in said housing yandvdividing said chamber into two portions;

latmospheric vent passage means in said housing and communicating withone of said chamber portions;

and passage means in said housing and communicating between the inletmanifold of said engine and the other of said chamber portions;

said disk spring and said pin member being ,axially movable inaccordance with the manifold vacuum in said engine to permit said pin toclean said metering orifice.

4. In a crankcase Ventilating valve for an internal combustion enginehaving an outlet therefrom and a metering orifice in said outlet, meansfor cleaning said orifice comprising:

a housing having a chamber formed therein;

movable partition means in said chamber and dividing said chamber intotwo portions;

passage means in said housing and communicating between one portion ofsaid chamber and an inlet manifold of said engine `and adapted toevacuate a portion of said chamber and move said partition means inresponse to vacuum pressure in the inlet manifold;

and a clean-out pin extending Ifrom said chamber and into said meteringorifice, said pin being secured to said movable partition and movabletherewith into tand out of said metering orifice in accordance with thevacuum in the intake manifold of said engine.

5. A crankcase Ventilating system for an interna-l combustion enginehaving an inlet manifold and a carburetor having a throttle valve andcomprising:

a housing having an inlet and first and second outlets, `said inletcommunicating with the crankcase of said engine, said first outletcommunicating with said intake manifold upstream of said throttle valveand said second outlet communicating with said intake manivfolddownstream of said throttle valve;

a check valve in said housing and operable to close said first outletwhen the vacuum in said intake manifold is above a predetermined value;

a metering orifice in said second outlet to control flow of crankcasegases therethrough;

and means for periodically cleaning said metering orifice, said meansincluding a pin reciprocab'le into and out of said orifice 'in responseto intake manifold vacuum in said engine.

6. The crankcase Ventilating system set forth in claim 5 wherein saidmeans for cleaning said metering orifice further include a chamberformed in asid housing and having a movable partition therein to dividesaid chamber into two portions, one of said portions being incommunication with said second outlet means for evacuating said one ofsaid portions, and said pin being secured to said movable partition forreciprocation into and out of said metering orifice.

7. The crank case Ventilating system set forth in claim 6 wherein saidmovable partition comprises a disk spring adapted to snap overcenter ineither direction in accordance lwith the vacuum in said inlet manifold.

References Cited in the file of this patent UNITED STATES PATENTSWinkler Nov. 22, 1944

1. CRANKCASE VENTILATING MEANS FOR AN INTERNAL COMBUSTION ENGINE HAVINGA CARBURETOR INCLUDING A THROTTLE VALVE AND AN INLET MANIFOLD ANDCOMPRISING: A VALVE BODY CONNECTED TO SAID CARBURETOR AND HAVING FIRSTAND SECOND OUTLET MEANS, SAID FIRST OUTLET MEANS COMMUNICATING WITH SAIDCARBURETOR UPSTREAM OF SAID THROTTLE VALVE, SAID SECOND OUTLET MEANSCOMMUNICATING WITH SAID CARBURETOR DOWNSTREAM OF SAID THROTTLE VALVE ANDINCLUDING A METERING ORIFICE; CONDUIT MEANS COMMUNICATING BETWEEN SAIDCRANKCASE AND SAID VALVE BODY AND COMMUNICATING WITH SAID FIRST ANDSECOND OUTLET MEANS; A CHECK VALVE IN SAID FIRST OUTLET MEANS ANDOPERABLE IN ACCORDANCE WITH THE AMOUNT OF SUCTION IN SAID INLET MANIFOLDTO DIRECT CRANKCASE GASES THROUGH EITHER SAID FIRST OUTLET MEANS OR SAIDSECOND OUTLET MEANS; AND VACUUM OPERATED MEANS FOR CLEANING SAIDMETERING ORIFICE, SAID MEANS BEING OPERABLE IN ACCORDANCE WITH THEAMOUNT OF SUCTION IN SAID INLET MANIFOLD.